High Zinc Density Crop Genotypes are a Solution in Alleviating Zn Malnutrition in India

Zinc (Zn) is an essential nutrient for human health and about 50% of Indian population are at the risk of its deficiency mainly due to consumption of low Zn food crops grown on Zn deficient soils. Biofortification of Zn in seed through mineral fertilization and breeding and selection for high grain Zn density crop genotypes increase the Zn intake in human. Indian effort on this, started about 15 years ago, in staple food crops are summarised here. The rice is a poor source of Zn and polished rice of common Indian rice varieties show <14 mg kg⁻¹ Zn, whereas the recent cultivars Chhattisgarh Zinc Rice1, BRRI Dhan-72 and IET 23832 had >20 mg kg⁻¹ Zn. The average grain Zn in wheat cultivars of India is about 25 mg kg⁻¹ and hence new high Zn cultivars Akshai, BHU5, Zinc Shakthi, Pusa wheat 111 (HD 2932), HI 1563 with 8–12 mg kg⁻¹ more Zn were developed. Groundnut is a good source of Zn with high variability (22–94 mg kg⁻¹ Zn in seed) among cultivars, and TKG 19A, ICGV 86590, M 145, M 197, Tirupati 3, CO 2, CSMG 884 and GG 7 are high Zn density cultivars with > 63 mg kg⁻¹ Zn in their seeds. In sorghum, CS 3541 and HC 308 are high Zn cultivars with > 40 mg kg⁻¹ Zn and NSH 703, GK 4035, Mahabeej 703 and NSH 702 are hybrids with > 31 mg kg⁻¹ Zn. Pearl millet contains 32–54 mg kg⁻¹Zn. Pulses are also rich in Zn (30–60 mg kg⁻¹), but due to presence of phytic acid, the bioavailability of Zn decreases. Also the foliar application of zinc sulphate increases 10–60% Zn in seed of various crops. These high Zn density crop cultivars need their extensive cultivation and consumption as food to ensure adequate Zn uptake and combat its malnutrition in India.